In optical transmission, applications exist wherein numerous optical signals carried by respective optical fibers must be switched or routed to a corresponding number of output fibers. Optical cross-connects have been used to provide this optical switching function. The U.S. Pat. No. 5,206,497, issued on Apr. 27, 1993 to B. H. Lee describes an optical cross-connect that uses a free-space optical switching apparatus.
Another type of optical cross-connect can be implemented using a large optical beam steering switch designed by using motor driven beam deflection clusters. Such an arrangement is disclosed in the pending application entitled "STRICTLY NON-BLOCKING SCALABLE MATRIX OPTICAL SWITCH" filed on Feb. 20, 1998 by B. H. Lee, Ser. No. 09/026,856, and assigned to the same assignee as the present application. In one of the Lee arrangements, the beam deflection clusters are mounted on both ends of the beam steering switch. When this optical beam switch is mounted horizontally in an integrated rack assembly, as shown in FIG. 1, access from the sides is required to replace the clusters. However, this violates the frontal accessibility requirement often specified by customers. Horizontal mounting also requires that the optical beam switch span across several integrated rack assemblies, because of its large size. Handling and transportation of the optical beam switch also becomes more difficult. Meeting Telcordia's Network Equipment Building Systems (NEBS) Requirements (e.g., GR-63-CORE, Issue 1) also becomes exceedingly difficult. These problems also increase when the cross-connect size increases.
When the optical beam switch is mounted vertically in a rack assembly, as shown in FIG. 2, then access to the beam deflection clusters requires access via the top and bottom, which is also not easy because of the size of the optical beam switch and the limited space in the rack assembly.
What is needed is an optical beam switch of reduced size and improved accessibility when mounted in a rack assembly.